Approved by the FDA in 1993 for treatment of anemia, Erythropoietin (EPO) is a 193 amino acid glycoprotein hormone, produced by the kidneys to regulate red blood cell (RBC) production; a process commonly termed erythropoiesis. EPO was originally identified as a cytokine that promotes erythrocyte progenitor survival and differentiation, but has also been shown to possess neuroprotective functions, particularly in response to ischemic injury in the central nervous system, (CNS). Clinical use of EPO has been prevalent in the treatment of anemic cancer patients, while ongoing studies are exploring EPO's potential in the treatment of neurological diseases (e.g. stroke). Notwithstanding, recent clinical studies in cancer patients have begun to uncover highly worrying adverse events, suggesting that administration of recombinant human EPO (rHuEPO) can adversely effect overall patient survival. An urgent need thus exists in medical oncology to better understand and predict the prevalence or susceptibility to this effect, so that administration of rHuEPO can be contra-indicated, continued or stopped.